XE Leaded Head to XF Unleaded Head

[winfield_blue]

Gday, am wanting to get some information as I have a leaded motor in me XF. It is definitly a XE Leaded motor and pings under acceleration. What i am wanting to know is what do i need to do to the head on the XE motor to make it unleaded. or is it just easier and cheaper to get an xf unleaded head from the wreckers. have been usin the valve master oil in with me oil, but i dont see it making my car run better. can someone please give me more info on xe head leaded to unleaded.